Kate Laughs Off Prince Harry's Marathon Prank

The couple, who will celebrate their one-year anniversary on April 29, were surprised by Harry, 27, last weekend who teased live on the BBC that they will be running the London Marathon next year. Despite public speculation that they'd be running the race, aides say his comment was in jest.

So when Kate was asked about her possible marathon plans during a chat with guest John Ions at a reception on Thursday, she had the perfect response.

Brushing her hair back, and looking slightly embarrassed, she said, "I think William's going to have to do something to get him back."

She told Ions, chief executive of an investment management business Lionstrust, which sponsored an expedition to the South Pole, "I'm more of a short distance runner. My sister's more of a longer-distance runner."

Ions hinted the couple hasn't ruled anything out, though. "It seems that it maybe something they will do in due course."